/*
 * $Id: ComboBoxAdaptor.java 4051 2011-07-19 20:17:05Z kschaefe $
 *
 * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
package org.jdesktop.swingx.autocomplete;

import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.accessibility.Accessible;
import javax.swing.JComboBox;
import javax.swing.JList;
import javax.swing.plaf.basic.ComboPopup;
import javax.swing.text.JTextComponent;

/**
 * An implementation of the AbstractAutoCompleteAdaptor that is suitable for
 * JComboBox.
 * 
 * @author Thomas Bierhance
 * @author Karl Schaefer
 */
@SuppressWarnings("nls")
public class ComboBoxAdaptor extends AbstractAutoCompleteAdaptor implements ActionListener {

	/** the combobox being adapted */
	private JComboBox comboBox;

	/**
	 * Creates a new ComobBoxAdaptor for the given combobox.
	 * 
	 * @param comboBox
	 *            the combobox that should be adapted
	 */
	public ComboBoxAdaptor(JComboBox comboBox) {
		this.comboBox = comboBox;
		// mark the entire text when a new item is selected
		comboBox.addActionListener(this);
	}

	/**
	 * Implementation side effect - do not invoke.
	 * 
	 * @param actionEvent
	 *            -
	 */
	// ActionListener (listening to comboBox)
	@Override
	public void actionPerformed(ActionEvent actionEvent) {
		markEntireText();
	}

	@Override
	public int getItemCount() {
		return comboBox.getItemCount();
	}

	@Override
	public Object getItem(int index) {
		return comboBox.getItemAt(index);
	}

	@Override
	public void setSelectedItem(Object item) {
		// SwingX 834: avoid moving when already selected
		if (item == getSelectedItem()) {
			return;
		}

		// kgs - back door our way to finding the JList that displays the data.
		// then we ask the list to scroll until the last cell is visible. this
		// will cause the selected item to appear closest to the top.
		//
		// it is unknown whether this functionality will work outside of Sun's
		// implementation, but the code is safe and will "fail gracefully" on
		// other systems
		Accessible a = comboBox.getUI().getAccessibleChild(comboBox, 0);

		if (getItemCount() > 0 && a instanceof ComboPopup) {
			JList list = ((ComboPopup) a).getList();
			int lastIndex = list.getModel().getSize() - 1;

			Rectangle rect = list.getCellBounds(lastIndex, lastIndex);

			if (rect == null) {
				throw new IllegalStateException("attempting to access index " + lastIndex + " for " + comboBox);
			}

			list.scrollRectToVisible(rect);
		}

		// setting the selected item should scroll it into the visible region
		comboBox.setSelectedItem(item);
	}

	@Override
	public Object getSelectedItem() {
		return comboBox.getModel().getSelectedItem();
	}

	@Override
	public JTextComponent getTextComponent() {
		// returning the component of the combobox's editor
		return (JTextComponent) comboBox.getEditor().getEditorComponent();
	}
}